WattNode WNC-3Y-208-MB, Инструкция по установке и эксплуатации

Страница: 42 / 62

42 Operating Instructions
PowerSum
This is the sum of the real power for active phases (line voltage above 20% of nominal). This can
include negative values, so if one phase is negative, it will reduce the reported
PowerSum .
Voltage Registers
All integer voltage registers are reported in units of 0.1 VAC, so 1234 = 123.4 VAC.
VoltAvgLN
This is the average line-to-neutral voltage (average of VoltA , VoltB , and VoltC ). Only active
phases are included (phases where the voltage is above 20% of nominal).
VoltA, VoltB, VoltC
These are the RMS AC voltages for each phase, measured relative to the neutral connection on
the meter. If neutral is not connected, then they are measured relative to the ground connection.
Voltage phases that are not connected may report small random voltages, but the WattNode
meter treats any phase reporting less than 20% of the nominal VAC as inactive and will not
measure power or energy on inactive phases.
VoltAvgLL
This is the average line-to-line voltage (average of
VoltAB
,
VoltBC
, and
VoltAC
). All phases are
included in the average.
VoltAB, VoltBC, VoltAC
The WattNode meter cannot directly measure line-to-line voltages. It provides these registers as
estimates of the line-to-line voltage. In order to estimate these voltages, the meter must know the
phase offset or the type of electrical service (see
PhaseOffset configuration register).
Frequency
Freq
The WattNode meter measures the AC line frequency in Hertz. The integer Freq register reports
the frequency in units of 0.1 Hz. All phases must have the same line frequency; otherwise this
value will be erratic or incorrect.
Advanced Registers
Per-Phase Energy Registers
EnergyA, EnergyB, EnergyC
The per-phase energy registers report the net real energy for each phase, where “net” means
negative energy will subtract from the total. This value is appropriate for net metering applications
(i.e. photovoltaic) where you wish to measure the net energy in situations where you may some-
times consume energy and other times generate energy.
These values are reset to zero when “1” is written to the ZeroEnergy register. You may also reset
them to zero or load preset values by writing to these registers.
Positive Energy
EnergyPosA, EnergyPosB, EnergyPosC
The per-phase positive energy registers measure the positive real energy for each phase.
Negative energy is ignored (instead of subtracting from the total). Energy is measured once per
second, so the determination of whether the energy is positive is based on the overall energy for
the second.